Data Harvest 1157-1 Quick Start Manual

The spirometer
Apparatus
Spirometer.
Pressure filter fitted
1 x filter per person to be tested
A spirometer is a device that measures
breathing patterns, lung capacities and
function. The Spirometer measures
accurately the flow of air through the device.
This investigation will allow you to calculate
the various lung capacities that can be
measured.
The spirometer flow head contains a sheet of
resistance material that restricts the flow of
air; the resistance to the airflow creates an
increase in pressure across it. The increase
in air pressure is measured via two air lines,
one inside the flow head and one inside the
instrument body. An air pressure sensor is
used to measure the changes in air pressure.
A second flow head is used by the test
subject to breathe into the spirometer. A
plastic guard is supplied to make it obvious
that one of the flow-heads is not for use by a
subject. The flow heads contain a filter that is
effective in trapping and blocking the
transmission of viral and bacterial particles
into the spirometer.
The air flow data can be converted to Volume using the spirometer displacement function in the software.
The volume of air that is breathed into and out of the lungs while at rest is called the tidal volume (TV), this is
normally around 0.5 of a litre and supplies the oxygen needed for the normal respiration of the individual at
rest.
Once exercise starts the need for oxygen increases, to increase the turnover of oxygen in the lungs the rate
of ventilation of the gas exchange surface must increase. Using yourself as a model, you can identify the
change in a breathing pattern with exercise – usually the breathing becomes deeper and quicker. This tells
us that the lung has reserves of volume that can be used for the increase in oxygen exchange required in
exercise.
The maximum you can inspire (breathe in) over the normal tidal inspiration is the Inspiratory Reserve Volume
(LRV).
The maximum you can expire (breathe out) over the normal tidal expiration is the Expiratory Reserve Volume
(ERV). The ERV is approximately 1/6th of the Total Lung Capacity (TLC)
The sum of the tidal volume, inspiratory reserve volume and expiratory Reserve Volume gives the vital
capacity (VC) of the lung.
The lungs can never be fully emptied of air, this remainder air volume that is in the lung after the maximal
forced expiration is the residual volume (RV). It is created by the volume inside the alveoli, trachea and other
tubes of the lungs. The residual volume can be approximated by converting the subject's mass into a
volume. The conversion is 0.45 kg = 1 cm
Revision 0
Data recording setup
You need to go fast to get the best results, 50 ms
inter-sample or shorter.
A trigger that rises above 0.2 l/s
See practical notes for more details.
Please make sure that you use the latest version
of EasySense2 or higher.
3 of volume.
1157-1
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